Australian Cattle Dogs, also called Blue Heelers or Queensland Heelers, were developed in nineteenth-century Australia to drive cattle over long distances in heat. They're compact and muscular, usually 35 to 50 pounds, with a short, weather-resistant double coat in blue or red speckle. Shedding is moderate, with heavier coat blows once or twice a year.
Heelers are loyal, clever and alert, often devoted to one person and reserved with strangers. Their herding instinct can show up as nipping at heels or chasing bikes, kids and other pets, which matters on busy sidewalks. Dogs vary, but most do best with consistent training, a real job and plenty of exercise. Many don't fully mature until around two years old.